From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH] [net-next] net: sched: avoid uninitialized variable use Date: Thu, 18 Jan 2018 15:32:22 +0100 Message-ID: <20180118143222.GB2063@nanopsycho.orion> References: <20180118131747.920324-1-arnd@arndb.de> <20180118134910.GA2063@nanopsycho.orion> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jamal Hadi Salim , Cong Wang , "David S. Miller" , David Ahern , Networking , Linux Kernel Mailing List To: Arnd Bergmann Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Thu, Jan 18, 2018 at 03:19:14PM CET, arnd@arndb.de wrote: >On Thu, Jan 18, 2018 at 2:49 PM, Jiri Pirko wrote: >> Thu, Jan 18, 2018 at 02:17:28PM CET, arnd@arndb.de wrote: >>>gcc has identified a code path in which we pass uninitialized >>>data into tc_dump_tfilter(): >>> >>>net/sched/cls_api.c: In function 'tc_dump_tfilter': >>>net/sched/cls_api.c:1268:8: error: 'parent' may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> >>>This initializes the variable to the value it had before the previous >>>change. >>> >>>Fixes: 7960d1daf278 ("net: sched: use block index as a handle instead of qdisc when block is shared") >>>Signed-off-by: Arnd Bergmann >>>---- >>>I don't know if my patch is the best way to address the issue, but >>>if not, then at least it helps show what the warning is about >>>and lets someone else come up with a better solution. >> >> I already sent a fix for this: >> http://patchwork.ozlabs.org/patch/862787/ > >Ok. I've looked at your patch for way too long now and still don't see how >you've shown it to be correct. Shouldn't there be a at least a comment >to explain why zero is an appropriate initialization value in that case? Okay. Will add comment. > > Arnd